A pressure vessel for containing fluid under pressure may include a tank, a closure cap, and a rupturable closure wall. In such a pressure vessel, the closure wall is fixed and sealed to the closure cap. The closure cap is fixed and sealed to an outlet end of the tank to close the tank. The closure cap thus supports the closure wall in a position in which the closure wall blocks the fluid from flowing outward from the tank. Additionally, the closure cap is constructed as a manifold with a plurality of fluid outlet openings.
When the fluid is to be released from the pressure vessel, the closure wall is ruptured. As known in the art, the closure wall may be ruptured by fluid pressure forces acting outward against the closure wall, or by the impact of a piston or the like. The fluid then flows outward past the closure wall and into the closure cap, and further outward from the pressure vessel through the outlet openings in the closure cap.
A pressure vessel of the foregoing type is commonly used to contain inflation fluid for inflating an inflatable device. For example, the pressure vessel may be used to contain inflation fluid for inflating an air bag which protects a vehicle occupant upon the occurrence of a vehicle collision. In such a pressure vessel, the closure wall typically is a dome-shaped metal disk which is welded to the closure cap.